Risk mitigation in divers with persistent (patent) foramen ovale.

Risk mitigation in divers with persistent (patent) foramen ovale. Diving Hyperb Med. 2019 Jun 30;49(2):77-78 Authors: Wilmshurst P Abstract In this issue, Anderson and colleagues report follow-up of divers who were found to have a persistent (patent) foramen ovale (PFO) or, in eleven cases, an atrial septal defect (ASD). In most divers diagnosis followed an episode of decompression illness (DCI). The efficacy of closure of the PFO/ASD in preventing future DCI was compared with conservative diving. They reported that in the closure group the occurrence of confirmed DCI decreased significantly compared with pre-closure, but in the conservative group this reduction was not significant. It is believed there are three requirements for a diver to suffer shunt-mediated DCI: A significant right-to-left shunt (usually a large PFO but sometimes an ASD or pulmonary arteriovenous malformation). Venous bubbles nucleated during decompression circumvent the lung filter by passing through the shunt. Target tissues are supersaturated with dissolved inert gas, so that they are able to amplify embolic bubbles. All three are required because DCI does not occur after contrast echocardiography when bubbles cross a right-to-left shunt. Therefore, there are two ways that a diver who has suffered shunt-mediated DCI may continue to dive - either their shunt is sealed or future dives should be so conservative that venous bubbles are not liberat...
Source: Diving and Hyperbaric Medicine - Category: Sports Medicine Tags: Diving Hyperb Med Source Type: research